Broccoli
Brassica oleracea var. italica
Broccoli is a rewarding cool-season crop that produces its best heads during mild subtropical weather. Fertile soil, consistent moisture and early pest protection are the keys to strong plants and reliable harvests.
Overview
At a Glance
Peak Planting Window
April to August
Seasonal Role
Cool-season staple crop
Difficulty
Moderate
Planting Method
Seedling preferred
First Harvest
10–16 weeks
Sun
Full sun
Water
High
Heat Tolerance
Low
Humidity Tolerance
Moderate (good airflow recommended)
Family
Brassicaceae
Category
Vegetable
Planting Calendar
Monthly Planting Guide
Month-by-month suitability for coastal subtropical Australia.
Rationale
Why This Planting Window
Broccoli performs best through the cooler months, when mild temperatures support steady growth and firm head development. Planting from autumn into winter helps avoid the heat stress and premature flowering that can reduce quality in coastal subtropical conditions.
Reference
Growing Information
Lifecycle
Biennial grown as an annual
Ideal Soil Temperature
10–24°C
Germination
5–10 days
Transplant Ready
4–6 weeks
Soil
Fertile, moisture-retentive, well-drained soil enriched with compost
Soil pH
6.0–7.5
Plant Spacing
45–60 cm
Row Spacing
60–75 cm
Frost Tolerance
Moderate
In the garden
Plant Care
Feeding
Prepare the soil with compost before planting and provide regular balanced feeding during active growth. Broccoli is a demanding crop and benefits from steady nutrition without excessive nitrogen late in development.
Watering Guidance
Keep the soil consistently moist, particularly during head formation. Avoid water stress, which can produce small heads and reduce side-shoot development.
Avoid Nearby
- Avoid repeatedly growing broccoli or other brassicas in the same soil, as this can increase pest and disease pressure.
Watch out for
Problems & Prevention
Common Pests
Cabbage white butterfly caterpillars, aphids, diamondback moth, snails and slugs.
Common Diseases
Clubroot, downy mildew, black rot and damping off.
Common Mistakes
Planting too late into warm weather, allowing plants to dry out, poor soil fertility, overcrowding and failing to protect young plants from caterpillars.
Picking
Harvest
First Harvest
10–16 weeks
Harvest Window
Harvest the main head at maturity, followed by side shoots where the variety allows
Harvest Indicators
Harvest when the central head is firm, compact and fully formed, before the flower buds begin to loosen or turn yellow. Cut the main head with a length of stem and leave the plant in place for possible side shoots.
Standard
SGGS Details
Subtropical Gardener Growing Standard — profile metadata.
- SGGS Code
- VEG006
- Version
- 1
- Confidence
- High
- Seasonal Role
- Cool-season staple crop
- Crop Champion Month
- June
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